Initially, Jenner’s company started selling lip kits for $29, according to the magazine. She has used social media as an advertising tool since. Her personal Twitter account has 25.6 million followers. About 110 million people follow Jenner on Instagram.

Jenner often posts images highlighting which Kylie Cosmetics products she’s wearing on Snapchat and Instagram, according to Forbes. She also posts videos that highlight product launches.

To create the list, Forbes evaluated the worth of each woman’s assets and stakes in public companies, according to the project’s methodology. Any woman who didn’t inherit their money was considered “self-made.” To be considered, women had to be U.S. citizens and have made all of their profits in the U.S.